More precisely, the guidance of the aircraft, in particular a military transport plane, is implemented at least over an intermediate trajectory between a first flight trajectory for a low-altitude flight, and a second flight trajectory which starts at an initial point, and from which trajectory a tactical landing is carried out.
The present invention applies therefore to a tactical landing, that is to say to a landing which is carried out on an unprepared runway, for example in the military field for discharging troops and hardware with a view to an unexpected action. To be able to carry out such a tactical landing under good conditions, it is necessary for the aircraft to arrive in a stabilized manner, at the right speed (with an appropriate acceleration), at the right altitude and in an aerodynamic configuration appropriate to said initial point corresponding to the start of said (second) flight trajectory, at the end of which the tactical landing will be carried out.
Additionally, to be able to carry out such a tactical landing as discretely as possible, the aircraft is generally made to fly along a low-altitude approach trajectory, up to said second flight trajectory, to allow the aircraft to benefit from masking by the terrain and thus not be easily detectable.
Moreover, to attempt to reach said initial point under the best possible conditions, the pilot of such an aircraft generally has at his disposal only information relating to a point of deceleration which is situated upstream of said initial point, and from which he is advised to decelerate the aircraft. However, this point of deceleration takes no account of the profile of the terrain on the approach to the landing zone, and the pilot must therefore manually adjust the piloting of the aircraft so as to reach said initial point under the aforesaid particular conditions, this of course being very difficult to achieve.